Electrical apparatus



N. SUGIMURA.

ELECTRICAL APPARATUS.

APPLICATION FILED JUNE 5,1919.

Patented Oct. 25, 1921..

2 SHEETSSHEET I.

Inventor'- Fig.2.

a t F LW i .m t a A k s H H w N. SUGRMURA. ELECTRICAL APPARATUS.

APPLICATION FILED JUNE 5, 1919.

1,394,951. Patented Oct. 25, 1921..

2 SHEETS-SHEET 2- v Invehtor": nobuchika irnura,

H is Aiiornely.

UNITED STATES PATENT OFFICE.

NOBUCHIKA SUGI HEURA, OF TOKYO, JAPAN, ASSIGNOR TO GENERAL ELECTRIC ICOMPANY, A CORPORATION OF NEW YORK.

ELECTRICAL APPARATUS.

Specification of Letters Patent.

Patented Oct. 25, 1921.

Application filed June 5, 1919. Serial No. 301,959.

To all whom it may concern:

Be it known that I, NOBUCHIKA Susi- MURA, a subject of the JapaneseEmpire, and resident of Tokyo, J a van, have invented certain new anduseful Improvements in Electrical Apparatus, of which the following is aspecification.

lly invention relates to tanks or containers for electrical apparatus,which are customarily made of sheet metal. The general objects of myinvention are to improve the construction of such tanks, to produce astrong and durable tank which may be sub jected to severe weatherconditions without being affected by corrosion, and to reduce the costof construction, transportation and installation of such tanks.

In the construction of electrical apparatus which is designed to becooled artificially such for instanceas transformers, some inductionregulators and the like, the tanksor containers for such apparatus mustbe sufficiently strong mechanically to support not only the apparatusitself but also the weight of the cooling medium that is contained inthe tank. This has resulted in bulky and rather heavy tanks which areexpensive both to manufacture, transport and install. As an alternativeto this it has been suggested to make such tanks of a plastic such asconcrete, which may be construe-tee at the place of installation, butthe difficulties to be overcome in making the plastic, especiallyconcrete, oil tight and proof against osmosis has heretoforeoffsetsubstantially all the advantages naturally attendant on the use ofsuch plastic.

In the practice of my invention, I have combined both the use of sheetmetal and plastic construction in a novel manner which yieldsconstruction embodying substantially the combined advantages of eachmaterial. The trunk or walls of the tank which are subject only tohydrostatic side thrust of the oil or insulating fluid within areaccordingly made of sheet metal which affords g'OOCl radiation, w rilethe base which is subject to severe compressional strains is made of theplastic, which is preferably reinforced; the interior surface being madeproof against osmosis by one or another of the novel cooperatingarrangement of parts hereinafter more fully set forth.

Further objects and advantages of my invention will appear from thefollowing detailed description when taken in connection with theaccompanying drawings in which:

Figure 1 shows a view partly in section and partly in elevation of atank for use in connection with transformers constructed to embody myinvention. Fig. 2 is a similar view of another form of tank differingfrom that shown in Fig. 1, constructed in accordance with my invention.Fig. 3 is a cross section through the plastic base of the tank shown inFig. 2; while Figs. 4, 5 and 6 show further modified constructions.

Referring now to the drawing, and to Fig. 1 in particular, 10 denote thetrunk or side walls of the tank for the transformer 11, shown assubmerged in the oil or other cooling medium 12 contained in the tank.The high and low tension leads for the transformer are shown at 13 and14 respectively and are shown as brought out through the cover of thetank in a convenient conventional manner.

The trunk 10 is made of sheet material, preferably mild teel plate,hZLVlIlg its edges secured in any convenient manner, as by riveting orwelding, so as to give it a cylindrival form. This trunk is secured in amolded base 15 made of plastic material, preferably concrete, althoughany suitable plastic may be used, as for instance, asphalt, cement,fibrocement and the like. This plastic base 15 is preferably reinforcedas shown by the means of a metallic lattice or screen 16 and a plate orrods 17. The lower rim of the trunk 10 is shown as distended in order tobe more securely held in place by the plastic 15; the latter being soformed as to engage a considerable portion of the lower surface of thetrunk both interiorly and exteriorly.

In order to make the plastic base 15 proof against osmosis, the innersurface of the base, which is exposed to the liquid 12 is covered with asheet 18 of thin metal. This sheet 18 is made to fit intimately theconfiguration of the interiorly exposed surface of. the base and at itsouter edge tightly abuts against the sides of the trunk 10.

The trunk without the base would generally be shipped to the place wherethe transformer is to be used, since suitable plastic material for thebase can, as a rule, be readily obtained at the place of installation.

At the place of installation the base 15 would accordingly be shaped insuitable molding forms, the trunk put in place and the whole left toset; after which the transformer itself would be put in place and thenthe proper amount of insulating fluid added to the content of the tank.

In Figs. 2 and 3, is shown a corrugated trunk 20, the corrugationsaffording a greater radiating surface than is afforded by the plainsurface of the trunk shown in Fig. 1.

The trunk 20 affords a housing for electrical apparatus indicated at '21whose terminal leads are shown at 22. A plastic base 23' is here shownas reinforced by the lattice 2%. Instead of the trunk 20 being insertedin the base 23 as it is left to set, the base 23 is shown as formed witha shallow pit 25- in its top surface; the sides and bottom of ablematerial indicated at 26. The upper edge of the pit is shown asreinforced by the wire or cable 27 passing around its periphery.

ihe lower end of the trunk 20, which is here shown as provided with anauxiliary bottom 28 of suitable material such astreated pressboard isinserted in this pit and an adherent-water proof filling material 29such as lead is inserted in the interstices around the edge of the pit25.'

In Fig. 4 I have illustrated how I may make the base 48 for the trunk 40impervious to oil or proof against osmosis in still another manner.-Here instead of a thin metal sheet intimately fitting the configurationof the interiorly exposed surface'of' the base, I rave used an asphaltcloth 425, though obviously any layer of impervious material soassociated with the base may be used. The edges of the cloth 45 areshown as bent down at 46 to make a snug engagement with the wall of thetrunk 4L0.

In Big. 5 I have shown still another construction for making the baseproof against osmosis. Here a thin auxiliary base of sheet metal 51 iswelded to the trunk and the whole set inthe plastic base 53 which isshown as preferably reinforced. Plastic material in this form of myinven-' tion engages with the auxiliary base 51 both interiorly andexteriorly.

In Fig. 6 I have illustrated still another 7 the pit being preferablyfaced with suitby a suitable surface treatment, which may' beaccomplished by a suitable coating of water-proof varnish. Theinterstices which may exist about the joint between the wall of thetrunk andthe plastic material of the base are here also filledpreferably with a lead packing which may be applied in molten condition.

The top rim for the tank may also be formed of' plastic as shown at 66which maybe set in any desired form by suitable molds and is preferablyreinforced as shown at 67.

While I have here shown and described several embodiments of myinvention which are, at present, the best means known to me for carryingthe sameinto effect, I would have it understood that they are merelyillustrative and that I do not mean to be limited thereby-tothe precisedetails shown, nor in the choice of equivalent arrangements except asdefined in my claims hereunto annexed. V

vVhat I claimas new and desire to-secnre by Letters Patent of the UnitedStates, is:

1. In a casingfor' liquid submerged electrical apparatus, thecombinationwith a trunk constructed. of sheet metal, of a plas tic baseformed to engage with a rim of said trunk, and'a thin metallic surfaceoverlying theinteriorly Xposed surface and theedge of the plastic aboutthe rim of said trunk adapted to render the same impervious to theliquid in the casing.

2. In a casing for liquid submerged electrical apparatus, thecombination with a trunk constructed of sheet metal, of a plas tic baseformed to engage with a rim of said trunk, reinforcing material embodiedin said base, and a liquid tight surface material intimately associatedwith said plastic for making its-interior surface and the rim about saidtank proof against osmosis.

In witness whereof, I' have hereunto set my hand thissixth day of May,1919.

NOBUCHIKA SUGIMURA. [1 8.

